drm/i915/gt: Pull marking vm as closed underneath the vm->mutex (ad2f9bc9) · Commits · 戴 / test

Pull the final atomic_dec of vm->open (marking the vm as closed) underneath the same vm->mutex as used to close it. This is required to correctly serialise with attempting to reuse the vma as the vm is closed by a second thread. References: ("drm/i915: Check that the vma hasn't been closed before we insert it") Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by:

Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200227085723.1961649-10-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_gtt.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -171,7 +171,9 @@ void __i915_vm_close(struct i915_address_space *vm)
		{
		struct i915_vma vma, vn;

		mutex_lock(&vm->mutex);
		if (!atomic_dec_and_mutex_lock(&vm->open, &vm->mutex))
		return;

		list_for_each_entry_safe(vma, vn, &vm->bound_list, vm_link) {
		struct drm_i915_gem_object *obj = vma->obj;

		@@ -186,6 +188,7 @@ void __i915_vm_close(struct i915_address_space *vm)
		i915_gem_object_put(obj);
		}
		GEM_BUG_ON(!list_empty(&vm->bound_list));

		mutex_unlock(&vm->mutex);
		}

drivers/gpu/drm/i915/gt/intel_gtt.h

+1 −2

Original line number	Diff line number	Diff line
		@@ -429,7 +429,6 @@ static inline void
		i915_vm_close(struct i915_address_space *vm)
		{
		GEM_BUG_ON(!atomic_read(&vm->open));
		if (atomic_dec_and_test(&vm->open))
		__i915_vm_close(vm);

		i915_vm_put(vm);

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